.MAS File Extension

Game file used by rFactor, a racing simulation game; stores the asset files for a racing track map and includes files for both the structure and the appearance of the track; can be modded to create custom tracks, but modding is only for advanced users.

MAS files can be opened with the gMotor MAS File Utility (MAS.EXE), which is part of the "rFactor mod development tool pack" available from the rFactor website.

Pre-written procedure or query used by an Access database.

Data file created by MEGA, a program used for testing evolutionary hypotheses; created in MEGA's Alignment Explorer tool and contains a binary representation of a genetic sequence alignment, which aligns genetic codes between two samples.

MAS files are used for saving the computed sequence alignment result and performing additional analysis such as generating phylogenetic trees (.MTS files).